Segments with fixed length
From JSXGraph Wiki
The underlying JavaScript code
var brd = JXG.JSXGraph.initBoard('box', {axis:false, boundingbox: [-5, 5, 5, -5]}),
p0 = brd.create('point', [-2,2], {withLabel:false}),
p1 = brd.create('point', [0,2], {withLabel:false}),
p2 = brd.create('point', [-2,0], {withLabel:false}),
p3 = brd.create('point', [0,0], {withLabel:false}),
p4 = brd.create('point', [-2,-2], {withLabel:false}),
p5 = brd.create('point', [0,-2], {withLabel:false}),
seg1 = brd.create('segment', [p0, p1], {withLabel:true, name:'seg1: free'}), // free segment
seg2 = brd.create('segment', [p2, p3, 2], {withLabel:true, name:'length 2'}), // segment of length 2
seg3 = brd.create('segment', [p4, p5, function(){ return seg1.L();}], {withLabel:true, name:'length of seg1'}); // segment has length of seg1